Tucson warned of 'dangerous' heat & fire-polluted air as blazing temps & hazy skies continue

Wildfires hundreds of miles away are continuing to make the air in Tucson thick with smoke particles, and a continuing heat wave means a warning about dangerous temperatures through Thursday.

Fires in central and northern California, and in the Four Corners region, are sending a blanket of smoke across the country — including in Tucson, where haze has been making it hard to see across the valley all week.

That particulate pollution, and ground-level ozone levels pushed by high temperatures, prompted Pima County to issue another "air quality health watch" on Wednesday.

The National Weather Service has issued an excessive heat warning through Thursday evening for Tucson and Pima County.

112-degree forecasts have officials cautioning about "dangerously hot conditions" across Arizona's deserts.

Highs of 107-112 are possible across Southern Arizona and western deserts.

In Tucson, thermometers could hit 107 on Wednesday, with Thursday nearly as hot, and still just a scant chance of relief from monsoon thunderstorms.

The heat warning will be in effect through 8 p.m. Thursday. While there's a slight chance of rain, most days will see less moisture than normal or late August.

"We may see an increase in thunderstorms early next week," NWS forecasters said.

"Very high heat risk will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities," officials said.

The hear warning area covers the Tucson metro area, the Tohono O'Odham Nation, western Pima County to Sells and Ajo, Nogales, the Safford area, and south central Pinal County, the National Weather Service said. The Phoenix area, Yuma and most of Arizona's western deserts are also covered. Gila Bend could see temps of 112, while Yuma might hit 115. Phoenix and the rest of that metro area could top out at 112.

Officials recommended that people limit outdoor chores and spend the afternoon and evening in air-conditioned buildings.

"Be prepared to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors," NWS officials said.

Officials also put out a reminder to never leave a pet, child, or anyone else in a parked car.

From the Weather Service:

Keep in mind you may need to adjust your plans based on the latest health and safety guidelines from CDC and your local officials. Cooling shelters may need to take your temperature or ask questions about how you are feeling.

Take extra precautions if you work or spend time outside. When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9-1-1.

Researchers at San Francisco State University conducted a study in 2003 that showed that the temperature inside a vehicle can rise to 114 degrees on a 95 degree day, and will rapidly rise to 140 in under an hour even with the windows open.

Air quality monitoring equipment captured levels of ozone exceeding federal health standards several times over the past week, a Pima County Department of Environmental Quality spokeswoman said.

"Hazy skies may continue throughout the week, potentially causing spikes in air pollution levels," said PDEQ's Karen Wilhelmsen earlier in the week.

"Wildfire smoke transported from California wildfires, as well as fires in our area, are likely a significant contributor to recent and current levels of ozone and particulates. In addition to motor vehicle exhaust, industrial and power plant emissions, gasoline vapors, chemical solvents and natural sources, wildfire smoke provides additional precursors that combine in the presence of sunlight to create ozone," she said.

Smoke from California and Colorado fires is "caught in a high pressure system over the Four Corners area," creating the conditions for ozone and haze across several Western states, including Arizona.

"It is possible that by the weekend, ozone levels may begin to drop if winds pick up and help ventilate smoke away from the area," PDEQ said Wednesday.

Smoke from the fires has been reported as far away as Kansas. In Tucson, the continued heat wave has exacerbated the effects of the smoke particles in the air.

From Pima County:

People who are sensitive to air pollution may experience shortness of breath, coughing, throat irritation, wheezing, and breathing discomfort. If sensitive to air pollution, individuals may want to limit outside exertion in the afternoon when elevated levels of ozone pollution are more likely to occur. Intense outdoor physical activity causes faster and deeper breathing, which allows ozone and particulates to penetrate into parts of the lungs that are more susceptible to injury.

Children, adults who are active outdoors, and people with respiratory diseases tend to be more sensitive to these pollutants. Individuals who are feeling symptoms should seek medical attention, if necessary.

Although wildfire smoke is a significant contributing factor in current ozone conditions, we can all help by taking controllable actions that reduce emissions, such as:

• Reduce driving - combine errands into one trip, ride the bus, bike, walk or share rides
• Avoid idling your vehicle’s engine. Refrain from long drive-thru lines - park and go inside instead
• Re-fuel your car after 6 p.m. when fumes are less likely to form ozone
• While re-fueling, always stop at the click to avoid spills and overfilling gas tank
• Make sure your gas cap is tightly sealed after re-fueling
• Check your tire pressure monthly to reduce gasoline use and associated air pollution
• Use low VOC or water-based paints, stains, finishes and paint strippers
• Avoid using gas-powered lawn and gardening equipment
• Conserve electricity to reduce emissions from power plants